As for McCain/Obama districts, the least McCain AZ districts seem to be the best shots (AZ-02 at 50-49 being the most plausible, followed by AZ-01 at 51-47).

Obama/Romney districts will mostly be the narrowly Obama districts from 2008. CT-04 (Fairfield County, home to lots of finance types) is probably the strongest Obama district (at 60%) that Romney has a reasonable chance at carrying.